Hi raywhite,

Thank you for posting in our forums!

You can get the old text of a node during the TextChanging event.  Once the TextChanging event returns and if the event was not cancelled, the node's text will get updated.  If it is not required to check the old text during the TextChanged event, I would recommend handling it during the TextChanging event.

You can use the following code to store the old text during textChanging and then access it during textChanged.

var oldText = null;
 function WebDataTree1_NodeEditingTextChanging(sender, eventArgs) {
     oldText = eventArgs.getNode().get_text();
 }
 function WebDataTree1_NodeEditingTextChanged(sender, eventArgs) {
     if (oldText != null) {
         console.log(oldText);
         oldText = null;
     }
 }

If you need further assistance with this, please let me know.